The first computer compatible characters of which I know were proposed by a gentleman in Prague about 1955. Since then several persons here in the States have proposed alternate configurations of such characters. The particular configuration of present interest was proposed several years ago (see U.S. Pat. No. 4,159,471) and appears to have significant advantages over other configurations. The master character of this set of characters is shown in FIG. 1. As indicated by that figure, a computer compatible character consists of a plurality of discrete elements. The character is computer compatible since each element can have a respective bit in a computer word. This bit is HI if and only if its respective element is PRESENT in the respective character.
The "EIGHT" at upper left of FIG. 1 means that the element indicated (when appearing by itself) is a numeral and represents the number "eight". The "A" at lower left means that the element designated (when appearing by itself) is to be ascribed the same meaning as the Roman letter "A". Likewise for the remaining elements. Subsets of the elements are to be combined to form other characters of the set of characters.
Combining the four numerical elements forms numerals of the hexadecimal numbering system. See FIG. 2. The number represented by each numeral is the sum of the weights of the elements present in that numeral. This is the second requirement for a set of characters to be "computer-compatible".
Combining the eight elements of FIG. 1 in all possible combinations permits a total of one hundred (hexadecimal) characters to be formed.
Combining the "A" with the numerical elements (including the Zero) forms an upper case alphabet--with a few characters left over. Combining the "a" element with the numerical elements forms a lower case alphabet. Over ninety (hexadecimal) characters are presently unassigned. They could be used to represent a host of phonemes.
The preferred bit assignment for the elements of the 8-element character is given in FIG. 3. The least significant bit corresponds to the "one" line. The most significant bit corresponds to the "A" line.
To memorize names for the full complement of one hundred (hex) characters would be difficult. It is also impossible--because there are no names for the unassigned characters. The problem is solved by breaking the 8-bit character into two hex numerals--as shown in FIG. 4. This technique is generally used in specifying bit patterns for computer words. The numerals of the hexadecimal numbering system together with their preferred names are given in FIG. 5. The numeral for "15" contains all the elements--it is a "master numeral".